Also possible are various kinds of stored-value cards that could offer, say, $10 or $20 or $50 worth of rides in a single purchase.

The stored-value cards can be programmed to hold any amount up to $1,000, which can be used at any participating store.

A so-called stored-value card, he explained, could be encoded with the digital equivalents of game tickets and cash.

Then again, in cooler moments we despise cash, so perhaps it is just as well that there is nothing romantic about a stored-value card.

This system allowed riders to use stored-value cards to access transit services.

Urbana is a stored-value card used on public transport services in Ljubljana, the capital of Slovenia.

"I hope in a year or so we are testing something with a stored-value card," Mr. Dent said.

Moreover, there is now no requirement that a company that issues stored-value cards must be a bank or regulated in any other way.

It calls for stored-value cards, not passes.

The actual postage is held electronically in small hardware devices that operate on the same principle as the stored-value cards issued by telephone companies.